Generally, in a case where drill boring is performed for a CFRP material, a large amount of cutting powder resulting from fine carbon fibers that are cut during the process is mixed in chips. In a case where such cutting powder scatters in a workshop, a working environment remarkably deteriorates. To cope with this, for example, a worker wears a dustproof workwear, or a dust protective mask. However, since the cutting powder is fine powder of carbon fibers that are harmful to a human body, more reliable recovery of the chips is demanded.
Heretofore, in order to improve a working environment, there is proposed a tool in which a cylindrical drill is mounted on the tip of a hollow machine spindle (spindle), and chips produced during a boring process are suction-recovered in a dust collector through a shank of the cylindrical drill and a hollow part (suction hole) of the machine spindle (Patent Document 1).
Additionally, in a tool using a cylindrical drill similarly, it is proposed to hollow out a work material with a cylindrical drill, and suck a hollowed cut core through a drill hole with a vacuum suction device, in order to reduce the production amount of chips (Patent Document 2).
In order to improve defects of these conventional techniques, this applicant has proposed a boring device in which a hollow spindle is used as a spindle that rotates with a driving source, and a cylindrical drill having an edge part on a tip thereof is mounted on a tip of the hollow spindle, a dust collection mechanism is coupled to a passage back end in the hollow spindle via a chuck, a work material is bored while the driving source rotates the cylindrical drill via the hollow spindle, so that chips and a cut core produced are suction-recovered in the dust collection mechanism through the passage in the hollow spindle (Patent Document 3, Patent Document 4).